Why is ethylene dibromide added to aviation gasoline?

Ethylene dibromide is added to aviation gasoline specifically for its ability to scavenge lead oxide from the combustion chamber of the engine. Aviation fuels often contain tetraethyl lead to improve their anti-knock properties. However, this lead can create lead oxide deposits in the engine, particularly in the combustion chamber and exhaust valves, which can hinder engine performance and longevity.

By adding ethylene dibromide to the gasoline, it effectively reacts with the lead oxide, helping to prevent or reduce the buildup of these deposits. This scavenging process ensures that the engine runs more efficiently and can maintain higher performance levels over time. Therefore, the primary function of ethylene dibromide in aviation fuel is to mitigate the negative effects of lead compounds, ensuring cleaner combustion and minimizing engine wear and fouling.